Little Pine State Park - Geology and Climate

Geology and Climate

Although the rock formations exposed in Little State Park and the Pine Creek Gorge are at least 300 million years old, the gorge itself formed about 20,000 years ago, in the last ice age. Pine Creek had flowed northeasterly until then, but was dammed by rocks, soil, ice, and other debris deposited by the receding Laurentide Continental Glacier. The dammed creek formed a lake near what would later be the village of Ansonia in Shippen Township in Tioga County, and the lake's glacial meltwater overflowed the debris dam, reversing the flow of Pine Creek. The creek flooded to the south and quickly carved a deep channel on its way to the West Branch Susquehanna River.

The land on which Little Pine State Park sits was part of the coastline of a shallow sea that covered a great portion of what is now North America about 300 million years ago, in the Pennsylvanian subperiod. The high mountains to the east of the sea gradually eroded, causing a buildup of sediment made up primarily of clay, sand and gravel. Tremendous pressure on the sediment caused the formation of the rocks that are found today in the Pine Creek drainage basin: sandstone, shale, conglomerates, limestone, and coal.

The park is at an elevation of 710 feet (220 m) on the Allegheny Plateau, which formed in the Alleghenian orogeny some 300 million years ago, when the part of Gondwana that became Africa collided with what became North America, forming Pangaea. Although the gorge and its surroundings seem to be mountainous, the area is a dissected plateau. Years of erosion have cut away the soft rocks, forming the valleys, and left the hardest of the ancient rocks relatively untouched on the top of sharp ridges, giving them the appearance of "mountains".

Five major rock formations from the Devonian and Carboniferous periods are present in Little Pine State Park and Cummings Township. The youngest of these, which forms the highest points in the township, is the early Pennsylvanian Pottsville Formation, a gray conglomerate that may contain sandstone, siltstone, and shale, as well as anthracite coal. Low-sulfur coal was once mined at three locations within the Pine Creek watershed. Below this is the late Mississippian Mauch Chunk Formation, which is formed with grayish-red shale, siltstone, sandstone, and conglomerate.

Next below these is the Mississippian Burgoon Sandstone, which is buff colored with shale, coal, and conglomerate inclusions. Below this is the late Devonian and early Mississippian Huntley Mountain Formation, which is made of relatively soft grayish-red shale and olive-gray sandstone. The lowest and oldest layer is the red shale and siltstone of the Catskill Formation, some 375 million years old. This layer is relatively soft and easily eroded, which helped to form the Pine Creek Gorge. The source of Little Pine Creek is on Mauch Chunk rock, and the stream cuts deeper as it flows south to Pine Creek. In the park Upper Pine Bottom Run has cut through layers of Burgoon sandstone and Huntley Mountain rock, and downstream of the park to its mouth the deepest parts of the valleys are made of the Catskill Formation.

The Allegheny Plateau has a continental climate, with occasional severe low temperatures in winter and average daily temperature ranges (difference between the daily high and low) of 20 °F (11 °C) in winter and 26 °F (14 °C) in summer. The mean annual precipitation for the Pine Creek watershed is 36 to 42 inches (914 to 1,070 mm). January is the coldest month at Little Pine State Park, July the warmest, and June the wettest. The highest recorded temperature at the park was 104 °F (40 °C) in 1988, and the record low was −19 °F (−28 °C) in 1982.